Interaction of 14-3-3 proteins with the Estrogen Receptor Alpha F domain provides a drug target interface
Interaction of 14-3-3 proteins with the Estrogen Receptor Alpha F domain provides a drug target interface
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DOI：
10.1073/pnas.1220809110
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发表时间：
2013-05-28
影响因子：
11.1
通讯作者：
de Boer, Albertus H.
中科院分区：
文献类型：
--
作者：
Leeuwen, Ingrid J. De Vries-van;Pereira, Daniel da Costa;de Boer, Albertus H.
雌激素受体α（ER α）参与许多生理和病理过程，包括乳腺癌。因此，乳腺癌治疗目前针对抑制ER α的转录效力，通过芳香酶抑制剂或竞争激素结合的抗雌激素阻断雌激素产生。由于耐药性，需要新的治疗方式，并且由于ER α二聚化对其活性至关重要，因此干扰受体二聚化提供了在药物设计中利用的新机会。在这里，我们描述了ER α二聚化如何通过与受体末端C末端14-3-3蛋白的相互作用来负向控制的独特机制。此外，小分子梭孢菌素（FC）稳定这种ER α/14-3-3相互作用。三聚体ER α/14-3-3/FC复合物的共沉淀为这种稳定提供了结构基础，并显示了倒数第二个苏氨酸（ER α-T-594）磷酸化对高亲和力相互作用的重要性。我们确认，T-594是一个独特的ER α磷酸化位点的乳腺癌细胞系MCF-7使用磷酸化T-594特异性抗体和质谱。与其ER α/14-3-3相互作用稳定作用一致，梭孢菌素减少雌二醇刺激的ER α二聚化，抑制ER α/染色质相互作用和下游基因表达，导致细胞增殖降低。因此，提供了ER α的独特功能性磷酸化位点和替代调节机制，以及选择性靶向该ER α/14-3-3界面的小分子。
Estrogen receptor alpha (ER alpha) is involved in numerous physiological and pathological processes, including breast cancer. Breast cancer therapy is therefore currently directed at inhibiting the transcriptional potency of ER alpha, either by blocking estrogen production through aromatase inhibitors or antiestrogens that compete for hormone binding. Due to resistance, new treatment modalities are needed and as ER alpha dimerization is essential for its activity, interference with receptor dimerization offers a new opportunity to exploit in drug design. Here we describe a unique mechanism of how ER alpha dimerization is negatively controlled by interaction with 14-3-3 proteins at the extreme C terminus of the receptor. Moreover, the small-molecule fusicoccin (FC) stabilizes this ER alpha/14-3-3 interaction. Cocrystallization of the trimeric ER alpha/14-3-3/FC complex provides the structural basis for this stabilization and shows the importance of phosphorylation of the penultimate Threonine (ER alpha-T-594) for high-affinity interaction. We confirm that T-594 is a distinct ER alpha phosphorylation site in the breast cancer cell line MCF-7 using a phospho-T-594-specific antibody and by mass spectrometry. In line with its ER alpha/14-3-3 interaction stabilizing effect, fusicoccin reduces the estradiol-stimulated ER alpha dimerization, inhibits ER alpha/chromatin interactions and downstream gene expression, resulting in decreased cell proliferation. Herewith, a unique functional phosphosite and an alternative regulation mechanism of ER alpha are provided, together with a small molecule that selectively targets this ER alpha/14-3-3 interface.